Device for drawing blood

ABSTRACT

A device for drawing blood includes a disposable holder ( 12 ) defining a socket ( 14 ) for receiving one end of a vacuum vial ( 18 ). The holder ( 12 ) includes an inner needle-receiving formation ( 26 ) and an outer needle-receiving formation ( 28 ), the inner and outer needle-receiving formations being in fluid communication with one another. A hollow needle ( 32 ) is connected to the inner needle-receiving formation ( 26 ) so as to extend into the socket ( 14 ) for puncturing a stopper ( 52 ) on the vacuum vial when the vial is inserted into the socket. The outer needle-receiving formation ( 28 ) carries a hypodermic needle ( 38 ) and a safety cover ( 42 ) for the hypodermic needle. The safety cover includes a cup ( 44 ) having an off-centre opening ( 46 ) through which the point of the needle ( 38 ) can pass, and a resilient member ( 48 ) for holding the cup over the point of the needle when the needle is inoperative so as to cover the point of the needle.

BACKGROUND OF THE INVENTION

THIS invention relates to a device for drawing blood.

Conventional devices for drawing blood include a vial having a syntheticrubber stopper. The vial is supplied with a lower internal pressure thanambient pressure and is commonly referred to as a vacuum vial or aVacutainer.

Generally, the vacuum vial is used in conjunction with a holder defininga socket for receiving the vial. The holder also defines an opening forreceiving a needle arrangement having an inner, hollow needle which isarranged to extend into the socket and an outer, hypodermic needle whichis arranged to extend outwardly from the holder, the inner and outerneedles being connected so as to be in fluid communication with oneanother.

To draw blood, the point of the hypodermic needle is introduced into apatient's vein, and thereafter the vacuum vial is inserted into theholder socket so that the inner needle puncture the vial stopper. Whenthis occurs, the pressure differential across the needle arrangement dueto the relatively low pressure in the vacuum vial causes blood to bedrawn through the needle arrangement and into the vial.

Various protective coverings for the hypodermic needle are available toprotect users from needle stick injuries. For example, WO 91/08787discloses a finger guard which is arranged to cover a hypodermic needleon a needle arrangement so that a user's hands are protected duringconnection of the needle arrangement to a holder or disconnection of theneedle arrangement from the holder. U.S. Pat. No. 5,295,972 alsodiscloses a finger guard for a hypodermic needle. In this case, thefinger guard includes an end cap with an off-centre opening forpreventing the point of the needle from inadvertently becoming exposed.

A problem associated with conventional devices for drawing blood is thatthe holder is used over and over again while the needle arrangement isused only once. Accordingly, each time blood is drawn from a patient, aneedle arrangement has to be connected to a holder and subsequentlydisconnected from the holder. Apart from taking time, the disconnectingof the needle arrangement from the holder after drawing blood from apatient involves the risk of a needle stick injury even where aprotective cover is used.

Furthermore, since the scan holder is used over and over again, it ispossible for blood in one sample to be contaminated by blood fromanother sample.

SUMMARY OF THE INVENTION

According to the invention there is provided a device for drawing bloodincluding:

a disposable holder which defines a socket for receiving one end of avacuum vial and which includes an inner needle-receiving formationprojecting into the holder and an outer needle-receiving formationprojecting outwardly from the holder, the inner and outerneedle-receiving formations being in fluid communication with oneanother, characterised in that

the inner and outer needle-receiving formations are incorporated intothe holder during manufacture so as to form a permanent part of theholder;

a hollow needle is connected to the inner needle-receiving formation soas to extend into the socket for puncturing a stopper on the vacuum vialwhen the vial is inserted into the socket;

a hypodermic needle is connected to the outer needle-receiving formationso as to extend outwardly from the holder; and

a safety cover is provided for the hypodermic needle, the safety coverincluding a cup having an off-centre opening through which the point ofthe needle can pass, and a resilient member for holding the cup over thepoint of the needle when the needle is inoperative.

The resilient member of the safety cover may comprise two limbs whichextend along the length of the hypodermic needle and which are arrangedto bias the cup into a position in which it covers the point of theneedle. In this case, the hypodermic needle can be expressed for use bythreading the point of the needle through the off-centre opening in thecup and drawing the cup back over the needle. When the safety cover isreleased after use, the resilient limbs automatically carry the cup backinto the position in which it covers the point of the needle.

In one embodiment of the invention, the inner and outer needle-receivingformations are formed integrally with the holder.

In another embodiment, the holder is formed from two parts and theneedle-receiving formations are integral with only one of the parts.

The needle-receiving formations may be designed to form a friction fitwith the needles.

Typically, at least one of the needles is connected to itsneedle-receiving formation by means of a Luer Slip or Luer lockattachment.

In a preferred form of the invention, a resilient, synthetic rubbersheath is arranged to cover the inner needle when this needle isinoperative.

The inner needle-receiving formation may include a bore for receiving aportion of the inner needs. In this case, the inner needle-receivingformation may have a head for engaging one end of the synthetic rubbersheath for covering the inner needle.

Preferably, the holder includes a series of gripping ribs on the outersurface thereof to facilitate the handling of the device.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in more detail, by way of exampleonly, with reference to the accompanying drawings in which:

FIG. 1 shows a cross-sectional view of a device according to the presentinvention with a vacuum vial;

FIG. 2 shows a cross-sectional view similar to that of FIG. 1 with thevacuum vial inserted into the device of the invention;

FIG. 3 shows a cross-sectional view of a portion of a device accordingto another embodiment of the invention in an unassembled condition;

FIG. 4 shows a cross-sectional view similar to that of FIG. 3 with thedevice in an assembled condition; and

FIG. 5 shows a cross-sectional view of a portion of a device accordingto a further embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1 and 2 of the drawings illustrate a first embodiment of a device10 for drawing blood according to the present invention. The device 10includes a disposable holder 12 which defines a socket 14 for receivingone end 16 of a vacuum vial 18. The holder 12 has a series of grippingribs 20 on a side wall 22 thereof, and is formed from a transparent ortranslucent plastics material so as to allow a user to see through theside wall 22 and into the socket 14.

An end wall 24 of the holder carries an inner needle-receiving formation26 which projects into the socket 14 and an outer needle-receivingformation 28 which projects outwardly from the holder, as shown. Theformations 26 and 28 are formed integrally with the holder 12 and areseen in FIGS. 1 and 2 to taper inwardly as they extend away from the endwall 24. The holder 12 also includes a bore 30 which extends between theneedle-receiving formations 26 and 28 so that these formations are influid communication with one another.

An inner, hollow needle 32 is connected to the inner needle-receivingformation 26 by means of a Luer Slip attachment 34 so as to be alignedwith the bore 30 and to extend into the socket 14, as illustrated. Aresilient, synthetic rubber sheath 36 is arranged to cover the needle 32when this needle is inoperative. The sheath 36 extends over the LuerSlip attachment 34 and is anchored within the socket 14 by the Luer Slipattachment.

On the other side of the end wall 24 an outer, hypodermic needle 38 isattached to the outer needle-receiving formation 28 by means of a LuerSlip attachment 40. This needle 38 is also aligned with the bore 30 andis arranged to extend outwardly away from the holder 12, as shown.

A safety cover 42 is connected to the needle 38 to prevent needle stickinjuries. Typically, the cover 42 is of the kind described in SouthAfrican patent 93/5510 and includes a cup 44 defining an off-centreopening 46, and a pair of resilient limbs 48 connected at one end of thecup 44 and at the other end to the Luer Slip attachment 40. The limbs 48are arranged to hold the cup 44 over the point 47 of the needle 38 whenthe needle is inoperative. In this condition (see FIG. 1) the point ofthe needle 38 and the opening 46 are not aligned with one another andthe safety cover has to be manipulated in order to expose the point ofthe needle.

The vacuum vial 18 is conventional in nature and consists of atransparent tube 50 formed from glass or a plastics material and asynthetic rubber stopper 52 for sealing tube. In practice, these sort ofvials are supplied with a lower internal pressure than ambient pressure.

To draw blood with the device 10, the hypodermic needle 38 is exposedand the point 47 of this needle is introduced into the blood stream of apatient. The needle 38 is exposed by aligning it with the opening 46 andthen carefully threading the needle through the opening by drawing thecup 44 back over the needle into the position illustrated in FIG. 2. Inthis position, the resilient limbs 48 are flexed outwardly and bias thecup 44 back towards the FIG. 1 position. Accordingly, the safety cover42 has to be held in the FIG. 2 position during use.

Thereafter, the vacuum vial 18 is inserted into the socket 14 asillustrated in FIG. 2. Initially, before the vacuum vial reaches theneedle 32, the resilient sheath 36 covers the point of these needle andprevents blood from draining through this needle point. However, whenthe vacuum vial 18 is fully inserted into the socket 14, the needle 32punctures the stopper 52 and the sheath 36 is driven away from the pointof this needle by the stopper, thereby exposing the point of the needle.As soon as the needle 32 penetrates the stopper 52 and enters the vial18, the pressure differential across the needles 32 and 38 causes bloodin the patient's blood stream to be drawn through the needles and intothe vial.

Once sufficient blood has been drawn, the vial 18 is removed from thesocket 14 so that the blood can be tested. As the vial is withdrawn fromthe socket, the resilient sheath 36 resumes its FIG. 1 position so as tocover the needle 32. Thereafter, the point 47 of the needle 38 isremoved from the patient's blood stream, and when this occurs theresilient limbs 48 automatically move the cup 44 back into the positionillustrated in FIG. 1. This reduces the likelihood of a needle stickinjury after the hypodermic needle has contacted the patient's blood.With the point of the needle 38 covered, the entire device 10 is thendisposed of.

FIGS. 3 and 4 illustrate a device 110 according to another embodiment ofthe invention. In this case, the holder 112 is formed in two parts whichare joined together. In FIG. 3, the two parts are illustrated detachedfrom one another prior to the final stage in the manufacturing process.As can be seen, one of the parts comprises an end wall 114 withintegrally formed inner and outer needle-receiving formations 116 and118, respectively, and the other part comprises a tubular housing 120.The end wall 114 carries a projecting formation 122 which is arranged toclip into a corresponding recess 124 in the inner face of the housing120. FIG. 4 illustrates the end wall 114 and the housing 120 connectedto one another to form the holder 112.

Apart from the two-part structure of the holder 112, the rest of thedevice is similar to the device 10 described above with reference to thefirst embodiment of the invention. Accordingly, the device 110 includesan inner needle 128 connected to the formation 116 by means of a LuerSlip attachment 130, an outer needle 132 connected to the formation 118by means of a Luer Slip attachment 134, a bore 136 extending between theformations 116 and 118, a resilient sheath 138, and a safety cover 140for the needle 132.

A third embodiment of a device 210 according to the invention isillustrated in FIG. 5. In this case, a holder 212 is formed as atwo-part structure, as in the case of the second embodiment, but here aninner needle-receiving formation 214 has a neck 216 and a head 218, asshown. An inner needle 220 extends into a bore 222 in an end wall 224 soas to be firmly secured to the end wall. In this regard, the needle 220may be arranged to form a friction fit with the bore 222 or it may beadhered to the side wall of the bore.

The head 218 is designed to form an anchor for a resilient sheath 226 soas to prevent this sheath from being withdrawn from the needle 220, inuse. Apart from the differences described above, the rest of the device210 is similar to the device 110 of the second embodiment of theinvention.

It should be appreciated that various other configurations could be usedto attach the needles to the holder. For example, instead of the LuerSlip attachment a Luer Lock attachment could be used.

An important feature of the invention is that the device includes asafety cover for the hypodermic needle which reduces the risk of aneedle stick injury. In addition, the inner needle is secured to theholder when the device is supplied to a user and is designed to bedisposed of with the holder. This avoids the need to connect the innerneedle to the holder prior to use and to disconnect the needle from theholder after use. Apart from saving time, this further reduces the riskof a needle stick injury.

Furthermore, the device of the invention is designed to be disposed ofwithout first removing the needles from the holder. Accordingly, unlikeconventional devices, the holder is used only once. This avoids thepossibility of one blood sample being contaminated by blood from anothersample drawn with the same holder.

What is claimed is:
 1. A device for drawing blood, comprising: adisposable holder which defines a socket for receiving one end of avacuum vial and which includes an inner needle-receiving formationprojecting into the holder and an outer needle-receiving formationprojecting outwardly from the holder, the inner and outerneedle-receiving formations being in fluid communication with oneanother; the inner and outer needle-receiving formations areincorporated into the holder during manufacture so as to form apermanent part of the holder; a hollow needle is connected to the innerneedle-receiving formation so as to extend into the socket forpuncturing a stopper on the vacuum vial when the vial is inserted intothe socket; a hypodermic needle is connected to the outerneedle-receiving formation so as to extend outwardly from the holder;and a safety cover is provided for the hypodermic needle, the safetycover including a cup having an off-center opening through which thepoint of the needle can pass, and a resilient member for holding the cupover the point of the needle when the needle is inoperative.
 2. A deviceaccording to claim 1, wherein the resilient member of the safety covercomprises two limbs which extend along the length of the hypodermicneedle and which are arranged to bias the cup into a position in whichit covers the point of the needle.
 3. A device according to claim 1,wherein the needle-receiving formations are designed to form a frictionfit with the needles.
 4. A device according to claim 3, wherein at leastone of the needles is connected to its needle-receiving formation bymeans of a Luer Slip or a Luer Lock attachment.
 5. A device according toclaim 1, wherein the inner needle-receiving formation which includes abore which is sized to receive a portion of the inner, hollow needle. 6.A device according to claim 1, comprising a resilient sheath which isprovided for covering the inner, hollow needle when this needle isinoperative.
 7. A device according to claim 1, wherein the holderincludes a series of gripping ribs on the outer surface thereof tofacilitate the handling of the device.